Quick-release valve



Nov; 2 1926.

H. D. MALLISON QUICK RELEASE VALVE INVENTOR (Jim 1..

Filed Nov. 8, 1924 ATTORN E [U Patented Nov. 2, 1926.

UNITED srarns PATENT OFFICE.

HARRY DOUGLAS MALLISON, O15 NEWARK, NEW JERSEY, ASSIGrNOR TO NATIONAL PNEUMATIC COMPANY, OF NEW YORK, N. Y., A CORPORATION OF WEST VIRGINIA.

QUICK-RELEASE VALVE.

Application filed November 8, 1924. Serial No. 748,784.

This invention is a quick release valve particularly adapted for use in conjunction with pneumatic motors. It is capable of general application in this connection, but is of special value in the door control systems of one man cars.

In such cars, one controller valve, operable by the motorman, is usually employed to control both the front and rear doors of the car. When the motorman operates the controller valve to close the doors, he, very naturally, waits until the front door, which is nearest to him, closes and thereupon starts the car. It is found, in practice, that, because of pipe line troubles, etc., the back door is generally a little later in closing than the front door, and, accordingly, it is not uncommon for acar to start while the back door remains'open and passengers are still in the act of boarding or leaving the car. Serious injury to passengers not infrequently results.

Cars of the character under consideration are generally provided with pneumatic safety equipment, i. e., the pneumatic door closing means interlocked with the car starting means so as to render the starting of the car conditional upon the closing of a door, but inasmuch as the starting means becomes effective as soon as the front door closes, accidents due to the delayed closing of the rear door are apt to result. The natural remedy which suggests itself is to increase the size of the exhaust opening in the main controller valve to accommodate the volume of air to be exhausted, but because of the safety interlock this is manifestly not feasible.

With the foregoing consideration in mind, the primary object of the present invention is to provide a quick release valve, particularly adapted for employment in connection with the pneumatic motor which controls the clos ng of the rear door of a one man car, and the purpose of which is to effect a quick release of the pressure from such motor, to the end that the operation of the motor may be rapid, and that the closing of the door may expeditiously be accomplished.

A further object is to provide a quick release valve unit which may be readily installed in present systems in a ready and economical manner andwit-hout requiring any pronounced modification in pipin or o I 1 07 associated operative ad uncts now 1n use.

In one of its preferred practical forms, the valve of this invention embodies a suitable casing Within which a piston is longitudinally operable. At one end of the casing a relatively large vent opening is provided and on the piston is mounted a sealing element cooperable with said vent opening. The end of the casing adjacent the vent opening is adapted to communicate with the pneumatic motor through suitable piping and the 0pposite end of the casing has communication with the controller valve. When the controller valve is shifted into a position to open the door, pressure is applied to the piston to seal the vent opening and sufficient pressure by-passes the piston to actuate or control the operations of the pneumatic motor. As soon, however, as the controller valve is returned to neutral or zero position, the pressure against the rear of the piston is relieved and the back pressure through the piping connection with the motor immediately retracts the piston and unseals the vent opening topermit instantaneous exhaust of such back pressure. In the absence of such pressure, the motor functions to close the door at once, expeditiously and without lag.

Further objects of the invention will ap pear more fully hereinafter.

The invention consists substantially in the construction, combination, location, and relative arrangement of parts, all as will be more fully hereinafter set forth, as shown by the accompanying drawings and finally pointed out in the appended claims.

Figure 1 shows the invention associated with a one pipe control system.

Flgure 2 shows the invention associated with atwo pipe control system.

Figure 3 is a vertical section of the quick release valve of this invention; and,

Figure 's an end view of said valve as it a pears from the left hand end of Figure 3.

Referring to the drawings, 1 designates a pneumatic motor and 2 a control valve having a controller handle 8. 4 is a feed pipe leading from a source of fluid under pressure to the control pipe. i

In Figure l, the pneumatic motor is shown as having a valve puller 5 associated therewith. This valve may be of any suitable construction and is preferably one of the conventional types embodying a piston adapted to be moved by compressed air in one direction and by a sprin in the opposite direction.

The control arm (3 of the motor is connected with the valve puller by a link or connecting rod 7, so that through the operation of the valve puller, the arm 6 is shifted in one direction or the other to control the operations of the pneumatic motor in the desired direction. a Y

Air is supplied to the valve puller through a pipe 8, which leads from the control valve 2 and in this pipe is included the valve of the present invention, the same being designated broadly by the reference character 9.

By reference particularly to Figure 3, it will be seen that the valve 9 comprises an elongated casing provided with a cylindrical bore in which a piston 10 is longitudinally operable. @ne end of the casing is provided with a relatively large exhaust or vent opening 11, about the inner end of which is formed an inwardly extending tubular portion constituting a valve seat 12. Asealing member 13 of any suitable material, adapted for tight engagement with the seat 12, is attached to the forward end of the pieton by a screw 1%, and when the piston is moved to the right, as viewed in Figure 3, this sealing member 13 will engage with the seat 12 and seal the exhaust opening 11. A spring 30 encircles the tubular extension forming the valve seat 12, and presses against the piston 10 to hold it normally unseated.

The opposite end of the casing is closed by a screw cap 15, which carries a plug 16 projecting into the rear end of the piston, which is hollowed out, as shown at 17, to allow of restricted longitudinal movement of the piston.

The casing is provided back ofthe rear terminal of travel of the piston with a tap ped hole 18 connected by one lead of the pipe 8 to the control valve and a tapped hole 19, beyond the forward terminal of travel ofthe piston, is connected by the other lead of the pipe 8 to the valve puller. The piston fits relatively loose in the cylinder and if desired may be longitudinally grooved or otherwise constituted to permit bypassing of pressure from one side ofthe piston to the other. The operation of the device, as thus far described, is as follows.

When the controller handle 3 is moved from the zero or neutral position into the position shown in Figure 1, fluid under pressure is permitted to pass from the port fed by the pipe l through the valve and through the adjacent lead of the pipe 8 to the interior of the valve casing 9 rearwardly of the piston. This pressure immediately acts upon the piston to force the sameinto a position to tightly seal the vent or exhaust opening 11, whereupon the pressure admitted back of the piston proceeds to bypass the piston, while holding it firmly to its seat, and passing through the pipe associated with the hole 19 is communicated to the valve puller. The pressure within the valve puller is applied to the piston therein and the operating arm 6 of the motor is shifted into a position to effect the operation of the motor in the desired direction.

7 YVhen a reversalof the operations which have been described is desired, the controller handle 3 is returned to neutral position and, inasmuch as the control valve is of the conventional form providing for an automatic venting the closing of the port associated with the pipe 4 is accompanied by a venting of that portion of the pipe 8, which leads to the interior of the casing 9 back of the piston 10. As soon as pressure'on the back of the piston is relieved, the back pressure from the valve puller exerts itself on the front end of the piston as well as spring 30 and i1ninediately retracts the latter allowing such back pressure to escape through the wide open exhaust or vent opening 11. As this vent opening is large, the escape of pressure is instantaneous and the valve puller is acted upon by the tension of its associated spring to shift the operating arm 6 instantaneously, so that the motor commencesto operate at once. In practice, the motor is connected to a door in any suitable manner, so that through the operations described, the door is opened and closed.

1 In adapting the present invention to the control of the doors of a one man car, the construction, as shown in Figure 1, is associated with a rear door and serves to eliminate the lag ordinarily incident to the closing thereof. In practice, the valve 9 is preferably positioned relatively close to the motor of the rear door, so that sluggishness incident to venting through longer pipe lines is eliminated.

In Figure 2, I have shown a two pipe system employed when a valve puller is not used, and where, in contradistinction, the fluid valve of the motor is matically. In this showing, the fluid valve is designated 20 and one side of the valve is connected to the controller valve 2 by a pipe 21, while the other side is connected through the valve 9 of the present invention to the controller by a pipe 22. When the controller handle 3 is shifted from neutral position to the full line position of Figure 2, pressure is admitted from the pipe 4 through the pipe 22 and through the valve 9 to the fluid valve 20, during which operation, the valve 9 will function in the manner hereinbefore described to permit the bypassing of the pressure around the piston which is utilized to simultaneously seal the vent or exhaust opening 11. If the controller handle is now shifted from the full operated pneu line position of Figure 2, to the dotted line position thereof, the chamber within the. casing back of the piston 10, will be immediately vented to permit of the exhaust of back pressure from the fluid valve through the exhaust outlet 11 and pressure will be simultanously admitted to the other side of the fluid valve through the pipe 21. Inasmuch as back pressure is immediately exhausted, the pressure admitted to the pipe 21 will function immediately to effect the operation of the motor.

It will thus be apparent that through the utilization of the valve operating piston 10 a very quick and positive control of the venting through a relatively large exhaust opening is obtained and it is found, in practice, that this arrangement will eliminate back pressure to such extent as to render the closing of the rear door of one man cars substantially coincident with the closing of the front door thereof. The danger of accidents is thus minimized and inasmuch as the motorman is more positive as to the closing of his doors, much time is saved and service is speeded up.

In the foregoing detailed description, I have set forth the invention particularly in conjuction with the control of doors of a one man car, but I wish it understood that the invention may be employed in other connections and as especially useful when used in conjunction with interlocked pneumatic and electrical controls in any connection.

Having thus fully described the invention, what I claim as new and desire to secure by Letters Patent is:

1. In a'quick release valve, the combina tion with a cylindrical casing, the wall of which is provided adjacent its opposite ends with openings with which pipes are adapted to be associated, a plug screwed into the forward end of the casing and having therethrough an exhaust opening terminating interiorly of the casing in a valve seat, a cap screw on the opposite end of the casing to close said end and provided interiorly with a projection extending longitudinally of the casing, of a piston mounted to reciprocate loosely within the cylinder between the projection and the valve seat, and carrying a sealing member at its forward end, whereby pressure admitted rearwardly of the piston will move the piston to engage the sealing member with the valve seat, while such pressure will bypass the piston and build up pressure at the opposite side thereof, said latter pressure serving to retract the piston to vent the casing when the pressure back of the piston is relieved.

2. In a system of thecharacter described, the combination with a pneumatic motor, a source of fluid under pressure, a control valve for controlling the feed of pressure from the source to the motor, and piping connections between the control valve and the motor, of a quick release valve comprising a casing provided with an exhaust opening, a piston valve operable within the casing and adapted in different positions to seal and unseal the exhaust opening, said casing being included in the piping connections between the control Valve and the motor, so that the flow of pressure from the control valve is through the casing and by the piston valve for the purpose of holding the piston valve in a position to close the exhaust opening so long as such pressure is maintained, said piston valve being automatically retractable to permit the escape of back pressure from the motor through the exhaust outlet when the feed of pressure from the source is discontinued at the control valve.

In testimony whereof I have hereunto set my hand on this twenty-seventh day of October A. 1)., 1924.

HARRY DOUGLAS MALLISON 

